Abstract
We compare, using single-particle optical imaging, trajectories of rotation and translation for micron-sized spheres in index-matched colloidal suspensions near their glass transition. Rotational trajectories, while they show intermittent caged behavior associated with supercooled and glassy behavior, explore a sufficiently wider phase space such that in the averaged mean-square angular displacement there appears no plateau regime, but instead sub-Fickian angular diffusion that follows an apparent power law in time. We infer translation and rotation time constants, the former being the time to diffuse a particle diameter and the latter being the time to rotate a full revolution. Correlation between time constants increases with increasing volume fraction, but unlike the case for molecular glasses, the rotation time constant slows more weakly than the translation time.
Original language | English (US) |
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Article number | 054905 |
Journal | Journal of Chemical Physics |
Volume | 135 |
Issue number | 5 |
DOIs | |
State | Published - Aug 7 2011 |
ASJC Scopus subject areas
- General Physics and Astronomy
- Physical and Theoretical Chemistry